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‣ Lectina dos rizomas de Arundo Donax L.: purificação,caracterização, propriedades,imuno-histoquímica e separação das isoformas; Arundo Donax L. rhizomes lectin : purification, characterization, properties, immunohistochemistry and separations of isoforms

Zanetti, Gilberto Dolejal
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Tese de Doutorado Formato: application/pdf
Português
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Algumas características como a falta de cristais de oxalato de cálcio, de estruturas secretoras e de tricomas, e a riqueza de fibras constituíndo estratos localizados imediatamente abaixo da epiderme e limitando o parênquima cortical, e formando bainhas vasculares, subsidia a autenticidade dos rizomas de Arundo donax. Além disto, os rizomas contem amido, cumarinas, alcalóides, flavonóides e saponinas não hemolíticas. Uma lectina (ADL) especifica para GlcNAc e seus derivados oligossacarídeos foi isolada e purificada dos rizomas de Arundo donax L. (Poaceae) por cromatografia de afinidade em matriz de estroma de coelhopoliacrilamida, resultando em uma purificação de 12,15 vezes, rendimento de 6,58% e recuperação de 80 % da atividade hemaglutinante. A lectina purificada é heterotrimérica com massa molecular aproximada de 32.900 estimada por gel de filtração e de 33.000 obtida por SDS-PAGE, em condições não desnaturantes e não redutoras. A lectina purificada possui elevado conteúdo de Glu/Gln, Asp/Asn, Gly e Cys, mas não é glicosilada. ADL é relativamente estável ao calor e ao pH, e resistente à digestão por enzimas proteolíticas. Ela aglutina eritrócitos nativos de coelho, porco e em menor intensidade de rato e humanos A...

‣ Algumas características da lectina de Arundo donax, L.

Bueno, Fernanda; Zanetti, Gilberto Dolejal; Filippon, Letícia
Fonte: Universidade Federal do Rio Grande do Sul Publicador: Universidade Federal do Rio Grande do Sul
Tipo: Conferência ou Objeto de Conferência Formato: application/pdf
Português
Relevância na Pesquisa
49.564307%

‣ Potencial energético da espécie Arundo donax l. (cana-do-reino) de ocorrência natural no Distrito Federal - DF; Energy potential species Arundo donax l. (cana-do-reino) natural occurrence in the Distrito Federal - DF

Oliveira, Giordano Bruno da Silva
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
Relevância na Pesquisa
51.08574%
Dissertação (mestrado)–Universidade de Brasília, Faculdade de Tecnologia, Departamento de Pós-Graduação em Ciências Florestais, Tecnologia e Utilização dos Produtos Florestais, 2014; No mundo há poucas tecnologias capazes de oferecer características de rendimento energético eficiente. Neste cenário, buscar novas fontes de energia, para complementar o setor energético, se torna bastante importante, pois os combustíveis fósseis possuem um ciclo fechado e estoque limitado. Assim, surgem as culturas energéticas que visam produzir biomassa como fonte produtora de energia sólida ou líquida. No Brasil, estas culturas, se baseiam no uso de eucalipto e capim elefante, porém, há outras fontes alternativas de biomassa eficientes. Entre elas, há a espécie Arundo donax L., com alta capacidade adaptativa para os diversos ambientes, alto índice de produção, alta eficiência energética, baixo custo de produção e exploração. Neste sentido, foi feito um estudo sobre o potencial energético da Arundo donax L., proveniente de ocorrência natural no Distrito Federal - DF, verificando seu potencial como fonte geradora de energia. Os colmos foram coletados no Distrito Federal, totalizando 753 indivíduos em 30 m² de área amostral. Os resultados mostraram altura média de 3...

‣ Bacterial community dynamics in horizontal flow constructed wetlands with different plants for high salinity industrial wastewater polishing

Calheiros, C.S.C.; Teixeira, A.; Pires, C.; Franco, A.R.; Duque, A.F.; Crispim, L.F.C.; Moura, S.C.; Castro, P.M.L.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2010 Português
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This study is focused on the diversity of bacterial communities from two series of horizontal subsurface flow constructed wetlands (CW) polishing high salinity tannery wastewater. Each series was planted with Arundo donax or Sarcocornia sp. in a substrate composed by expanded clay and sand. Chemical and biochemical oxygen demand removal efficiencies were similar in each series, varying between 58 and 67% (inlet COD 218 ± 28 mg L−1) and 60 and 77% (inlet BOD5 37 ± 6 mg L−1), respectively. High numbers of culturable bacteria were obtained from substrate and root samples – 5.75 × 106-3.95 × 108 CFU g−1 recovered on marine agar and 1.72 × 107-8.46 × 108 CFU g−1 on nutrient agar. Fifty bacterial isolates were retrieved from the CW, related phylogenetically to Firmicutes, Actinobacteria, Bacteroidetes, α-, β-, and γ-Proteobacteria. Changes in the bacterial communities, from roots and substrate of each series, related to the plant species, hydraulic loading rates and along CW operation were examined using denaturating gradient gel electrophoresis (DGGE). The clustering analysis suggested that a diverse and distinct bacterial community inhabits each series, which was related to the type of plant present in each CW.

‣ Evaluation of side-effects of glyphosate mediated control of giant reed (Arundo donax) on the structure and function of a nearby Mediterranean river ecosystem

Puertolas, L; Damasio, J; Barata, C; Soares, AMVM; Prat, N
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Português
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The aim of this study was to evaluate the effect of the application of the herbicide Herbolex (Aragonesas Agro, S.A., Madrid, Spain) to control giant reed (Arundo donax), which has glyphosate as active ingredient, on the structure and function of a nearby river ecosystem. Specifically, we assessed glyphosate environmental fate in the surrounding water and its effects on transplanted Daphnia magna, field collected caddisfly (Hydropsyche exocellata) and on benthic macroinvertebrate structure assemblages. Investigations were conducted in the industrialized and urbanized Mediterranean river Llobregat (NE Spain) before and after a terrestrial spray of glyphosate. Four locations were selected to include an upstream site and three affected ones. Measured glyphosate levels in river water following herbicide application were quite high (20-60 mu g/l) with peak values of 137 mu g/l after three days. After 12 days of its application, leaching of glyphosate from sprayed riverbanks was quite high in pore water (20-85 mu g/l) but not in the river. Closely linked with the measured poor habitat and water physicochemical conditions, macroinvertebrate communities were dominated by taxa tolerant to pollution and herbicide application did not affect the abundance or number of taxa in any location. Nevertheless...

‣ Effect of temperature and prey in the biology of Scymnus subvillosus (Goeze) (Coleoptera: Coccinellidae)

Sebastião, Dalila Carla Barbosa
Fonte: Universidade dos Açores Publicador: Universidade dos Açores
Tipo: Dissertação de Mestrado
Publicado em 18/12/2013 Português
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Dissertação de Mestrado, Biotecnologia em Controlo Biológico, 18 de Dezembro de 2013, Universidade dos Açores.; Scymnus subvillosus (Goeze) é um predador afidífago presente no Arquipélago dos Açores (Portugal), que ocorre em baixas densidades., recentemente, foi observado a explorar Melanaphis donacis (Passerini) em Arundo donax L. O Scymnus spp., embora menos estudadas, têm sido nos últimos anos, alvo de investigação na perspectiva da sua utilização como agentes de controlo biológico. Este estudo teve como objetivo determinar os efeitos concomitantes de quatro temperaturas constantes (15° C, 20 °C, 25 C e 30°C) e de três espécies de afídeos na sobrevivência e desenvolvimento dos estados imaturos de S. subvillosus , para obter a adequação ecofisiológica de M. persicae, A. fabae e M. donacis e finalmente a voracidade e fisiologia nutricional da fase larval L4 alimentadas com A. fabae . O tempo de desenvolvimento a partir de larvas a adulto diminuiu com o aumento da temperatura, variando de 61,5 dias a 15 º C para 10,4 dias a 30ºC. Para completar o desenvolvimento pré -imaginal com M. donacis, LDT foi calculado obtendo o valor de 11,7ºC e SET 196,3ºD. A 15ºC, as larvas não se desenvolveram quando alimentadas com A. fabae e M. persicae...

‣ Otimização da produção de xilitol por estirpes de Debaryomyces hansenii em hidrolisado de Arundo donax

Bandeira, Filipa de Sousa
Fonte: ISA/UTL Publicador: ISA/UTL
Tipo: Dissertação de Mestrado
Publicado em //2012 Português
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Mestrado em Engenharia Alimentar - Processamento de Alimentos - Instituto Superior de Agronomia; Arundo donax L. is a Mediterranean energy crop with a high potential for the production of bioenergy and added-value products. Nevertheless, its exploration within a biorefinery framework still requires further developments. This work aims to contribute for the development of a strategy to upgrade its hemicellulose fraction, by means of xylitol bioproduction. The raw material was milled and the influence of particle size on acid hydrolysis was studied. The composition of the hydrolysates and residual solids obtained did not differ significantly for the different fractions tested (< 2 mm). Three Debaryomyces hansenii strains were compared in chemically defined medium (CDM), and their tolerance and acclimatization were studied using non-detoxified hydrolysate-based medium (HM). Strain CCMI 941 presented the highest xylose consumption rate (0.26 g·L-1·h-1) in CDM and the best tolerance to the HM. For this reason, this strain was selected for the optimization of the xylitol bioprocess. The best results for xylitol yield and productivity in overall process (0.77 g·g-1 and 0.09 g·L-1·h-1, respectively) were obtained under semi-aerobic conditions...

‣ Arundo donax L. reed: new perspectives for pulping and bleaching. 5. Ozone-based TCF bleaching of organosolv pulps

Shatalov, A.A.; Pereira, H.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2008 Português
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Three selected alkali-based organosolv pulps (alkali-sulWte-anthraquinone-methanol (ASAM), alkali-anthraquinone-methanol (organocell) and ethanol-soda) from agroWbre crop giant reed (Arundo donax L.) were bleached by an ozone-based TCF (totally chlorinefree) bleaching sequence AZERQP (where A is an acidic pulp pre-treatment, Z is an ozone stage, (ER) is an alkaline extraction in the presence of reducing agent, Q is a pulp chelating, P is a hydrogen peroxide stage) without oxygen pre-bleaching, and compared with a conventional kraft pulp used as a reference. The diVerent response on bleaching conditions within each bleaching stage was noted for all tested pulps. The pulp bleachability, in terms of brightness improvement or lignin removal per unit of applied chemicals, was found higher for the organocell pulp. The ASAM and ethanol-soda pulps showed the highest bleaching selectivity, expressed by viscosity loss per unit of lignin removed or brightness improved. The overall bleaching results of organosolv pulps were superior to kraft.

‣ Controlo de cana (Arundo donax) em zonas ribeirinhas

Monteiro, Ana; Moreira, Ilídio; Moreira, Jorge F.
Fonte: CTFC / ISAPress Publicador: CTFC / ISAPress
Tipo: Parte de Livro
Publicado em //2012 Português
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RICOVER; Giant reed (Arundo donax) is a tall perennial grass widespread throughout the Mediterranean region. Despite its use to make musical instrumentals, building material, erosion control, windbreak, and renewed interest in bioenergy production it become a major invasive weed problem in watersheds because of its high competitive ability. Here, the biology and identification of giant reed and related species, e.g. common reed (Phragmites australis) and the weed negative effects are revised. Giant reed once established leads to loss of biodiversity. It also interferes with rivers by increasing sedimentation and narrowing water channels causing flooding, damage to bridges and stream bank erosion and increased costs of management. The management strategies are also revised. Finally the case-studies of giant reed control in Portugal are presented. Giant reed growth can be suppressed by repeated mowing combining with chemical control. This requires treating the weed with a systemic herbicide at appropriate times of the year to ensure translocation to the roots and rhizomes. Glyphosate (2.5% to 5% of commercial solution with 360 g a.i./L) applied after flowering showed to be effective but repeat applications, at least during two to three years...

‣ Fitoremediação de águas residuais contaminadas com Zn ou Cu utilizando Arundo donax L.

Costa, Fernando Jorge Gomes da
Fonte: Universidade Nova de Lisboa Publicador: Universidade Nova de Lisboa
Tipo: Tese de Doutorado
Publicado em /09/2014 Português
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A maioria dos países está demasiado dependente dos combustíveis fósseis para satisfazer as suas necessidades energéticas, em todos os seus principais sectores de actividade. A produção de culturas energéticas tem vindo a ser equacionada como uma alternativa muito promissora para substituir parcialmente esses recursos fósseis na produção de energia. De entre as diversas espécies, preferencialmente não alimentares, que podem ser cultivadas com o intuito de utilizar a sua biomassa para produzir energia, o Arundo donax apresenta-se como uma das mais promissoras, devido à sua elevada produtividade, resistência a baixos regimes hídricos, característicos dos países mediterrânicos nos meses de Verão, e a pragas. Para além do potencial de utilização como cultura energética, o Arundo donax também apresenta capacidade para remover metais pesados do substrato onde se encontra estabelecido, podendo ser utilizado para remover contaminantes do solo e das águas residuais. A utilização de águas residuais para irrigação de culturas energéticas, permite, não só, contrabalançar a escassez ou a sazonalidade da precipitação, mas também reduzir a necessidade de utilização de fertilizantes, combinando assim vantagens ambientais e económicas. Neste trabalho...

‣ Structural and mechanical design of tissue interfaces in the giant reed Arundo donax

Rüggeberg, Markus; Burgert, Ingo; Speck, Thomas
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Português
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The culms of the giant reed Arundo donax represent slender tube-like structures. Several nodes along the culm, a ring of sclerenchymatous fibres in the periphery of the culm wall and numerous isolated vascular bundles enclosed by fibre rings in the culm wall function as stiffening elements. The bundles are embedded in lignified parenchyma. Micromechanical analysis indicated differences in stiffness between the individual tissues of more than one order of magnitude. In case of abrupt transitions in stiffness at the interfaces, stress discontinuities arise under dynamic loads. This eventually leads to critical shear stresses at cell ends, and culm failure may be initiated at these points. Pronounced mechanical differences between individual tissues can be compromised by gradual transitions at their interfaces. Ultrastructural and spectroscopic investigations with high spatial resolution revealed a gradual transition of cell parameters (cell wall area fraction and cell length). However, cell wall parameters (cellulose microfibril angle and lignin content) showed abrupt transitions or remained almost constant across the interfaces between various tissues. The design principles found at the interfaces between tissues in the culm walls of A. donax are discussed as an adaptation strategy to mechanical loads at different levels of hierarchy.

‣ Cadmium Phytoremediation by Arundo donax L. from Contaminated Soil and Water

Sabeen, Maria; Mahmood, Qaisar; Irshad, Muhammad; Fareed, Iftikhar; Khan, Afsar; Ullah, Farid; Hussain, Jamshaid; Hayat, Yousaf; Tabassum, Sobia
Fonte: Hindawi Publishing Corporation Publicador: Hindawi Publishing Corporation
Tipo: Artigo de Revista Científica
Português
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The potential of Arundo donax L. for phytoextraction of cadmium (Cd) from contaminated soil and water was probed. The plants were grown under greenhouse conditions in pots containing a nutrient solution or soil with increasing doses of Cd (0, 50, 100, 250, 500, 750, and 1000 μg L−1) for 21 days. The growth and physiology of plants were evaluated at the end of the experiment. The maximum Cd content in root was 300 μg g−1 during hydroponics experiments over 230 μg g−1 in soil experiment. Cd concentration in stem was 262 μg g−1 at 750 μg L−1 supplied Cd in hydroponics over 191.2 μg g−1 at 1000 in soil experiment. The maximum Cd concentration in leaves from hydroponics was 187 μg g−1. Relatively low Cd uptake occurred during soil experiment with low translocation factor (TF) values. Both Bioaccumulation Factor (BF) and TF values for hydroponics were greater than 1. The IC50 values of ABTS and DPPH showed that both time and increasing Cd concentrations affected the production of antioxidants with lower half maximal inhibitory concentration (IC50) value on the 21st days. A. donax showed better potential for Cd remediation of aquatic environments.

‣ Combining the effects of process design and pH for improved xylose conversion in high solid ethanol production from Arundo donax

Palmqvist, Benny; Lidén, Gunnar
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em 01/05/2014 Português
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The impact of pH coupled to process design for the conversion of the energy crop Arundo donax to ethanol was assessed in the present study under industrially relevant solids loadings. Two main process strategies were investigated, i.e. the traditional simultaneous saccharification and co-fermentation (SSCF) and a HYBRID design, where a long high temperature enzymatic hydrolysis step was carried out prior to continued low temperature SSCF, keeping the same total reaction time. Since acetic acid was identified as the major inhibitor in the slurry, the scenarios were investigated under different fermentation pH in order to alleviate the inhibitory effect on, in particular, xylose conversion. The results show that, regardless of fermentation pH, a higher glucan conversion could be achieved with the HYBRID approach compared to SSCF. Furthermore, it was found that increasing the pH from 5.0 to 5.5 for the fermentation phase had a large positive effect on xylose consumption for both process designs, although the SSCF design was more favored. With the high sugar concentrations available at the start of fermentation during the HYBRID design, the ethanol yield was reduced in favor of cell growth and glycerol production. This finding was confirmed in shake flask fermentations where an increase in pH enhanced both glucose and xylose consumption...

‣ Degradative actions of microbial xylanolytic activities on hemicelluloses from rhizome of Arundo donax

Lama, Licia; Tramice, Annabella; Finore, Ilaria; Anzelmo, Gianluca; Calandrelli, Valeria; Pagnotta, Eduardo; Tommonaro, Giuseppina; Poli, Annarita; Di Donato, Paola; Nicolaus, Barbara; Fagnano, Massimo; Mori, Mauro; Impagliazzo, Adriana; Trincone, Antonio
Fonte: Springer Publicador: Springer
Tipo: Artigo de Revista Científica
Publicado em 09/07/2014 Português
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Polysaccharidases from extremophiles are remarkable for specific action, resistance to different reaction conditions and other biotechnologically interesting features. In this article the action of crude extracts of thermophilic microorganisms (Thermotoga neapolitana, Geobacillus thermantarcticus and Thermoanaerobacterium thermostercoris) is studied using as substrate hemicellulose from one of the most interesting biomass crops, the giant reed (Arundo donax L.). This biomass can be cultivated without competition and a huge amount of rhizomes remains in the soil at the end of cropping cycle (10–15 years) representing a further source of useful molecules. Optimization of the procedure for preparation of the hemicellulose fraction from rhizomes of Arundo donax, is studied. Polysaccharidases from crude extracts of thermophilic microorganisms revealed to be suitable for total degradative action and/or production of small useful oligosaccharides from hemicelluloses from A. donax. Xylobiose and interesting tetra- and pentasaccharide are obtained by enzymatic action in different conditions. Convenient amount of raw material was processed per mg of crude enzymes. Raw hemicelluloses and pretreated material show antioxidant activity unlike isolated tetra- and pentasaccharide. The body of results suggest that rhizomes represent a useful raw material for the production of valuable industrial products...

‣ Fuelling genetic and metabolic exploration of C3 bioenergy crops through the first reference transcriptome of Arundo donax L.

Sablok, Gaurav; Fu, Yuan; Bobbio, Valentina; Laura, Marina; Rotino, Giuseppe L; Bagnaresi, Paolo; Allavena, Andrea; Velikova, Violeta; Viola, Roberto; Loreto, Francesco; Li, Mingai; Varotto, Claudio
Fonte: BlackWell Publishing Ltd Publicador: BlackWell Publishing Ltd
Tipo: Artigo de Revista Científica
Português
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The development of inexpensive and highly productive biomass sources of biofuel is a priority in global climate change biology. Arundo donax, also known as the giant reed, is recognized as one of the most promising nonfood bioenergy crops in Europe. Despite its relevance, to date no genomic resources are available to support the characterization of the developmental, adaptive and metabolic traits underlying the high productivity of this nonmodel species. We hereby present the first report on the de novo assembly of bud, culm, leaf and root transcriptomes of A. donax, which can be accessed through a customized BLAST server (http://ecogenomics.fmach.it/arundo/) for mining and exploring the genetic potential of this species. Based on functional annotation and homology comparison to 19 prospective biofuel Poaceae species, we provide the first genomic view of this so far unexplored crop and indicate the model species with highest potential for comparative genomics approaches. The analysis of the transcriptome reveals strong differences in the enrichment of the Gene Ontology categories and the relative expression among different organs, which can guide future efforts for functional genomics or genetic improvement of A. donax. A set of homologs to key genes involved in lignin...

‣ Relationships between leaf anatomical features of Arundo donax and glyphosate efficacy; Parâmetros morfoanatómicos foliares de Arundo donax e eficácia do glifosato

Monteiro, Ana; Teixeira, Generosa; Moreira, Jorge Frazão
Fonte: SCAP Publicador: SCAP
Tipo: Artigo de Revista Científica
Publicado em //2015 Português
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Cuticle thickness is known to affect the amount of active ingredient that reaches the target site of a post emergence herbicide and consequently its efficacy. So, this work aimed to relate glyphosate efficacy with the thickness of leaf cuticle of young and mature leaves of Arundo donax. Glyphosate was applied at different development stages of the invasive species, in spring, summer and autumn at the concentrations of 0.675; 1.350 and 2.025 g L-1. Cuticle thickness of mature and young leaf blade and leaf sheath was measured on transverse sections by light microscopy. Despite the significant differences in the cuticle thickness between young and mature leaves, this did not seem affect the efficacy of glyphosate uptake since no significant differences were observed between young and mature leaves glyphosate treatments. But herbicide efficacy was dependent of the plant development stage. Higher efficacy of glyphosate was recorded when plots were sprayed at the end of October (flowering) compared to end April and mid June applications. Mortality of giant reed was higher than 90% one year after treatment only in autumn treatments. This result suggests that other mechanisms are involved, probably the reserves carrying over to rhizomes...

‣ Nuevos registros de presencia para Arundo donax L. (Poaceae) en Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
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Arundo donax L. es una gramínea altamente invasora, originaria de Asia y que está presente en Chile. El presente trabajo reporta nuevos registros de presencia para la especie en las regiones de O´higgins, Maule y Biobío. Se incluye una descripción morfológica y del habitat de la planta.; Arundo donax L. is a highly invasive grass, native of Asia and is present in Chile. This paper reports a new records of the specie in the regions of O'higgins, Maule and Biobío. A morphological and habitat description of the plant is included.

‣ Ocorrência e caracterização da espécie invasora Arundo donax L. (CANA-DO-REINO) no Distrito Federal, Brasil

Simões, Kenya Carla Cardoso
Fonte: Universidade de Brasília Publicador: Universidade de Brasília
Tipo: Dissertação
Português
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Dissertação (mestrado)—Universidade de Brasília, Departamento de Ecologia, Programa de Pós-Graduação em Ecologia, 2013.; A degradação do solo e dos ecossistemas nativos e a dispersão de espécies exóticas são as maiores e mais amplas ameaças à biodiversidade do Cerrado. Arundo donax L. (CANA DO REINO) é uma espécie invasora vigorosa que se estabeleceu e espalhou em habitats ripários com clima quente. Uma vez estabilizada, essa espécie se espalha rapidamente, substituindo a vegetação nativa, causando vários impactos no ecossistema. O estudo aqui apresentado tem por objetivo determinar a ocorrência e caracterizar a espécie invasora Arundo donax L. (CANA-DO-REINO) no Distrito Federal, Brasil. Através do mapeamento das populações, observou-se que a maior concentração da espécie está localizada na região central do Distrito Federal e que a presença dessa espécie está relacionada a áreas antropizadas, tais como: rodovias, aterros, depósitos de entulhos (bota-fora) e locais em obras. Após a análise de sementes coletadas no Distrito Federal, não foi encontrada nenhuma espigueta cheia, o que corrobora os trabalhos realizados nos Estados Unidos. E não foi encontrada, com a utilização do marcador molecular do üpo RAPD. uma variabilidade genética entre os indivíduos coletados. Arumdo donax apresentou...

‣ Biomechanics of the giant reed Arundo donax

Spatz, H.-Ch.; Beismann, H.; Brückert, F.; Emanns, A.; Speck, Th.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 29/01/1997 Português
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The quantitative description of local buckling of hollow plant stems requires the knowledge of Young's modulus in the longitudinal and tangential directions for the different tissues of which the stem is composed. For thick-walled stems the shear modulus for the radial-tangential plane is needed for an advanced treatment of the process of ovalization. The primary causes of failure can be predicted if critical compressive strains in the longitudinal direction and critical tensile strains in the tangential direction are known. All of these mechanical properties and their variation along the length of the stem can be measured in Arundo donax.

‣ Fluidised bed combustion of two species of energy crops

Abelha, Pedro; Franco, Carlos; Lopes, M. Helena; Gulyurtlu, Ibrahim; Cabrita, Isabel
Fonte: Laboratório Nacional de Energia e Geologia Publicador: Laboratório Nacional de Energia e Geologia
Tipo: Conferência ou Objeto de Conferência
Publicado em /05/2009 Português
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The use of biomass fuels for energy production through combustion has a growing application worldwide mainly for two reasons: first, the utilization of biomass for energy contributes to mitigate emission of green house gases; second, its use decreases the dependence of imported fossil fuels in Europe. The objective of this work was to study the combustion behaviour of two endogenous biomass species: cardoon (cynara cardunculus) and arundo (arundo donax), which were specially produced in energy crops plantations. Mixtures of cardoon and a forestry biomass specie (eucalyptus) were also studied to evaluate potential benefits from synergies between both biomass fuel types. The results showed that the utilization of cardoon, in pelletized form, and loose arundo as feedstock, did not give rise to any operational problems related with the feeding system. It was verified that the mono combustion of cardoon could pose problems at industrial scale in fluidised bed systems, considering the high levels of HCl and NOX emissions obtained and tendency to sinter the bed sand material. The addition of the forestry biomass to cardoon appeared to prevent the bed agglomeration problem. Furthermore, both the NOX and SO2 emissions were found to decrease at the same time suggesting potential synergy of blending different types of biomass regarding pollutant emissions and in bed agglomeration problems.